The invention relates to a method for degassing a conveyor chamber of a metering pump, and a device for implementing the latter.
The problem of gas formation in conveyor chambers of metering pumps is known, in particular when metering liquids. Gas formation takes place not just during the metering processes, but also when the pump is between metering operations. In the case of degassing substances like hydrogen peroxide H2O2, gas is released, wherein the number and size of gas bubbles in the conveyor chamber grow for the time metering is suspended or during an idle period. The pressure in the metering chamber rises as a result. If the pressure in the metering chamber of the pump exceeds the pressure in the pressure line, the pressure-side pump valve opens, followed by a transfer of liquid from the metering chamber of the metering pump into the pressure line, bringing about a pressure compensation. Therefore, the ratio between the gas volume and liquid volume in the metering chamber of the pump increases, so that metering volumes are not immediately output when starting up the metering pump. The metering process is thus suspended.
This being the case, it is desirable to provide a method for actuating metering pumps that improves the startup properties, along with corresponding metering pumps suitable for this purpose.